Many soils suffer from poor hydraulic conductivity, i.e., reduced or inefficient movement of water, nutrients and oxygen through the soil. In agricultural crops the problem is usually addressed by turning the soil prior to each planting. In large grassy areas, such as golf courses and public parks where the soil cannot effectively be turned, the problem is often addressed by punching numerous small holes in the top of the soil. Unfortunately, these and all commercially practical mechanical methods only improve hydraulic conductivity at a macroscopic level. Moreover, repeated compaction, use of chemical fertilizers, and frequent irrigation tend to re-create or exacerbate the problem with uncomfortable rapidity. The problem even affects ordinary homeowners, who often notice that their lawns need more fertilizer and more water each year to achieve the same results.
There are chemical technologies for improving hydraulic conductivity through aeration of soils. For example, U.S. Pat. No. 3,912,490 to Boghosian (October 1975) teaches direct addition of urea peroxide or hydrogen peroxide to the soil, often with a heavy metal catalyst. Urea peroxide is considered especially advantageous because it is highly mobile, the urea increases the stability of H2O2, and urea peroxide is non-toxic at high concentrations. Frankenberger, W. T., Factors Affecting the Fate of Urea Peroxide Added To Soil”, Bull Environ. Contam. Toxicol. (1997) 59:50-57. Calcium peroxide has also been used to increase oxygen levels, especially in clayey soils where it can significantly improve hydraulic conductivity. Note that these and all other referenced extrinsic materials are incorporated herein by reference in their entirety. Where term definitions are inconsistent between or among references, the broader or broadest definition applies.
Peroxides can also improve hydraulic conductivity by increasing total microbial populations and species diversity. U.S. Pat. No. 5,264,018 to Koenigsberg et al. (November 1993), for example, describes microbial decontamination of soil using high concentrations of metal peroxides (calcium, potassium, or magnesium), along with a surfactant (preferably 0.1 to 1% wt/wt of monolaurate, monopalmitate, monostearate, or monooleate ester or sorbitol, with or without ethoxylation) and an oxygen release modifier (preferably a source of simple phosphate ion). Interestingly, although the '018 patent appreciates the effect of peroxides on microbial populations, it fails to appreciate that such changes may be advantageous to growth of plants.
One drawback of using large quantities of peroxides is that they can sterilize the soil, thereby destroying substantially all of the “good” microbes. For example, U.S. Pat. No. 5,607,856 to Moon et al. (March 1997) teaches use hydrogen peroxide, peracetic acid, sodium peroxide, potassium peroxide, calcium peroxide, potassium oxide, and magnesium peroxide in sufficient quantities to sterilize soil for bioremediation. In such instances soil must be re-inoculated with beneficial bacteria and fungi for plants to grow effectively.
Non-peroxide sources have also been use to oxygenate soils. For example, U.S. Pat. No. 6,173,526 (January 2001) to Mazzei, teaches irrigating soils with oxygen infused water. While it is known that there are microbial sources of oxygen growing in a soil, extrinsic chemicals that can be manufactured and distributed in bulk, and that are neither ionic nor peroxides, have been largely or completely overlooked as materials for soil oxygenation. That is a considerable oversight since at least some fertilizer materials, including for example nitrates, are good oxygenators.
Fertilizers are sometimes combined with surfactants to enhance plant growth. For example, U.S. Pat. No. 6,206,946 to Hayashi et al. (March 2001) teaches a foliage spray containing a fertilizer, a surfactant, and a heptonic acid. U.S. Pat. No. 5,747,419 to Ishimoto et al. (May 1998) teaches a foliage spray using an iron cyanide fertilizer with a surfactant. US20040069032 to Krysiak et al., (April 2004) uses water soluble polyacrylamides (PAMs) in combination with a surfactant. Browning U.S. Pat. Nos. 5,391,542 (Feb. 1995) and 5,143,939 (September 1992), teach use of a specific surfactant such as UNION CARBIDE'S™ TERGITOL™ 15-S series of ethylene oxide derivatives to enhance plant growth, and to control nematode, worm, mite, and fungus. U.S. Pat. No. 6,460,290 to Moore (Oct. 2002) uses a fertilizer in combination a surfactant and alkyl polyglycoside. In U.S. Pat. No. 6,300,282 to Cooley (Oct. 2001), surfactants are applied to the soil after planting to maintain soil moisture levels near the potato root zone, and to prevent leaching of nutrients. Preferred surfactants are PREFERENCE™, a non-ionic surfactant blend containing soybean based fatty acid and alcohol ethoxylates; LI-319™, a non-ionic surfactant mixture of linear primary alcohol ethoxylates, ACTIVATOR N.F.™; a non-foaming, non-ionic wetting agent, surfactant, penetrant and spreader containing primary aliphatic oxyalkylated alcohol, dimethylpolysiloxane and adjuvant; WET-SOL 99™, a non-ionic surfactant containing poly(oxy-1,2 ethanediyl), alpha-(nonylphenyl)omega-hydroxy and a polysiloxane emulsion; ADVANTAGE FORMULA ONE™, a surfactant containing ammonium laureth sulfate, nonyl phenol ethoxylate; and ACTIVATOR 90™, a biodegradable, low-foaming, non-ionic surfactant and penetrant containing primary alkyl polyoxyethylene ether and free fatty acids and adjuvants. Again, none of these references teach, suggest or motivate one of ordinary skill in the art to provide a soil additive having a surfactant and a significant chemical source of oxygen.
The usual combination for promoting plant growth is a large quantity of fertilizer with a small to large quantity of surfactant. For example, U.S. Pat. No. 6,460,290 (October 2002) and U.S. Pat. No. 6,826,866 (December 2004) to Moore at al. describe aqueous compositions containing 65-99% fertilizer and 1-35% of a surfactant system. Similarly, U.S. 2004/0031305 to Kober et al., (publ. February, 2004) teaches a combination of 5-40% ammonium nitrate with 0.1-5% surfactant.
It is also known that a solution containing a small to large quantity of an oxygenator can be combined with small quantities of surfactants to reduce odors in air, sewage systems, on trash heaps and so forth. See WO04108173 to Alfrey et al., (December 1004). Such solutions apparently work by shifting microbial populations from anaerobic to aerobic metabolism, thereby reducing noxious smells that would otherwise derive from the anaerobic metabolism.
What appears to have been completely unappreciated is that the same solutions that are effective to treat odors can also be applied to soils or other plant growth media to promote plant growth. Thus, the Moore patents described above suggest nitrate as a fertilizer, but have no mention whatsoever of nitrate as an oxygenator, let alone contemplate using combinations containing nitrate as odor reducers. Still further, it has been completely unappreciated that odor treating compositions having low fertilizer and low surfactant concentrations can be extremely effective in promoting plant growth.